VL53L4CD Low Power mode power consumption?

XXXXQ · ‎2022-07-09

Hi,

I am trying to find a low power solution for close range (down to 1mm) proximity detection at 1Hz frequency. It seems VL53L4CD can do the job pretty good but I didn't find power consumption details of low power mode in the datasheet.

I also found there is a Ultra Low Power driver for VL53L3CX which only consumes ~50uA@1Hz but it doesn't support close-range. Can VL53L4CD achieve something similar wrt power consumption?

Thanks!

John E KVAM · ‎2022-07-11

Wow, you have not asked an easy question.

Basically, integration time is what gives us accuracy. A four fold increase in the integration time, will give a two fold increase in accuracy.

The UltraLowPower (ULP) driver saves power by decreasing the integration time. But at the expense of accuracy. We went so low, we can only see if something is there or not.

The other trick is the ToF sensors are about +/- 3% accurate, but that breaks down at the closer distances. The VL53L4CD in my testing is +/- 2mm at 7mm. (And that assumes you are not looking at really black surfaces and really reflective surfaces.

(The issue seems to be that the photons are taking multiple bounces between the target and the structure that's holding the sensor.)

I'm pretty sure you could run the ULP driver on the L4CD, but the accuracy issues would remain. You could tell something was in front of you, but not exactly where.

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View solution in original post

John E KVAM · ‎2022-07-11

Wow, you have not asked an easy question.

Basically, integration time is what gives us accuracy. A four fold increase in the integration time, will give a two fold increase in accuracy.

The UltraLowPower (ULP) driver saves power by decreasing the integration time. But at the expense of accuracy. We went so low, we can only see if something is there or not.

The other trick is the ToF sensors are about +/- 3% accurate, but that breaks down at the closer distances. The VL53L4CD in my testing is +/- 2mm at 7mm. (And that assumes you are not looking at really black surfaces and really reflective surfaces.

(The issue seems to be that the photons are taking multiple bounces between the target and the structure that's holding the sensor.)

I'm pretty sure you could run the ULP driver on the L4CD, but the accuracy issues would remain. You could tell something was in front of you, but not exactly where.

Our community relies on fruitful exchanges and good quality content. You can thank and reward helpful and positive contributions by marking them as 'Accept as Solution'. When marking a solution, make sure it answers your original question or issue that you raised.

ST Employees that act as moderators have the right to accept the solution, judging by their expertise. This helps other community members identify useful discussions and refrain from raising the same question. If you notice any false behavior or abuse of the action, do not hesitate to 'Report Inappropriate Content'

XXXXQ · ‎2022-07-14

Thank you @John E KVAM !

Very helpful answer especially the fact that I can run ULP on L4CD.